How the Finch Stole Christmas - S6-E9
Continuity mistake: When Romano is operating on the heart patient Valerie, Lucy has an instrument inside the patient. The shot then changes so that we can see her face and as she says, "Dr. Romano," there is no longer anything in her hand and she is holding it up waiting for a nurse to pass her an instrument, which she takes, but then the shot goes behind her - she now has a different instrument in her hand, which is in a different position.
Answer: It was in "Chaos Theory", the first episode of season 9 (time code 00:13:55).
Super Grover ★